284
Hi guys ,I need help to find the radius of curvature for this exercice:

A metal bar is 1.75m long with a coefficient of thermal expansion of 1.34*10-5K-1. It is rigidly held between two fixed beams. When the temperature rises, the metal bar takes on the shape of the arc of a circle.
What is the radius of curvature of the circle when the temperature rises by 40 degrees celcius?

hint:for small angle: sin(x)=x-x3/6.